"We've seen shoppers continue their spending frenzy into the New Year," he says.

"Initially we saw bigger ticket items walking off the shelves, now the focus has swapped to apparel and footwear, while household items have also been popular.

"Department stores have also had strong foot traffic, with our figures anticipating a 4.7 percent increase for the category compared to last year," he said.

Victoria will see the lion's share of the post-Christmas shopping growth, up 5.6 percent to $4.2 billion across the 21-day period tracked by ARA and Roy Morgan, followed by NSW at 3.8 percent growth and $5.3 billion.

"It's great to see shoppers out in force at retail stores, in what is typically the busiest spending period of the year," Zimmerman says.